0210812011 U.S. Nuclear Regulatory Commission Operations Center Event Report Paze /

General Information (PAR) Event# 46403

Rep Org: VELAN INC Notification Date / Time: 11/08/2010 16:02 (EST)Supplier: FLOWSERVE Event Date / Time: 09/15/2010 (EST)

Last Modification: 02/08/2011

Region: Docket #:City: QUEBEC, CANADA Agreement State: No

County: License #:State:

NRC Notified by: VICTOR APOSTOLESCU Notifications: KATHLEEN O'DONOHUE R2DOHQ Ops Officer: MARK ABRAMOVITZ PART 21 GP VIA EMAIL

Emergency Class: NON EMERGENCY RONALD BELLAMY R1DO10 CFR Section: ANN MARIE STONE R3DO

21.21 UNSPECIFIED PARAGRAPH VINCENT GADDY R4DO

PART 21 REPORT - LIMITORQUE LIMIT SWITCH DEFECT

The following report was received via fax:

"During the performance testing of our valves equipped with Limitorque SMB-00 we found that the limit switchcontacts proved to be defective. These tests took place in July 2010. Flowserve was advised and sent inreplacement parts that were installed by their representatives. The valve-actuator assemblies were cycled andproper operation was assessed. These valves have been shipped to Dominion Virginia. At the time we consideredthe issue isolated and did not pursue an in-depth corrective action response from the Supplier.

"Later in September when testing three valves equipped with Limitorque SMB-00 and two valves equipped withLimitorque SMB-2-06, we found again that the limit switch contacts were defective, exhibiting similar problems asfound earlier in July. These valves are still at our factory, awaiting the response and corrective action fromFlowserve.

"The limit switch boxes (4 gear train limit switches, 16 sets of contacts) appear to be identical on the two types ofactuators mentioned above.

"Upon closer examination, we determined that construction and installation elements appear poorly controlled,resulting in unexpected failure to operate due to the contact blade (called finger base by the Manufacturer) notreturning to a position where it can make contact again. This was documented internally on a Velan internaldeviation report on September 3, 2010.

"We advised Flowserve of our findings on September 15 and issued a formal Corrective Action Request (CAR25500-73903) on September 16, 2010, with a deadline for responding that expired on October 26, 2010. After a

02/08/2011 U.S. Nuclear Regulatory Commission Operations Center Event Report Page 2

General Information (PAR) Event# 46403

number of follow-ups, we managed to make contact with responsible personnel at Flowserve on October 29. Anevaluation report (electrical continuity test performed on sample switch assemblies cycled 2000 times) wassubmitted to our attention by Flowserve. However, we determined that the test did not answer all our concerns andrequested Flowserve to provide additional information. Currently the supplier is engaged in retrieving the defectiveparts from our facilities and performing additional examinations and tests. The Manufacturer expects to have allnecessary tests, examinations and evaluations completed on or before November 19, 2010.

"Based on functional testing performed at Velan we determined that we have no record of similar defects on valve-actuator assemblies produced prior to these events, we therefore believe that the root cause is relatively recent butthere is no way to know until Flowserve analyzes and evaluates the deficiency.

"This type of defect has the potential to affect other valve manufacturers who may have installed Limitorqueactuators equipped with this type of limit switch but we cannot say if such deviation could create a substantialsafety hazard."

* * * UPDATE FROM VICTOR APOSTOLESCU TO DONALD NORWOOD VIA FACSIMILE AT 0804 EST ON

1/24/2011 * * *

On January 14, 2011, Velan received the final report from Flowserve concerning limit switches identified in thisnotification. Velan has accepted the conclusions in the report.

The following is a synopsis of those conclusions: It was determined that producing a bend in the contact fingercannot occur during normal cyclic operation of the rotor. It is highly likely that the cause of the bent fingerassemblies was due to the use of a flat blade screwdriver. A flat blade screwdriver can also exert enough force todamage the cotter pin hole in the spring stud. Based on testing and evaluations of all returned Velan switches andswitches from Flowserve stock, a design deficiency has not been identified. Properly set switches will perform theirintended functions. A maintenance update will be issued by Flowserve to guide the industry on anyrecommendations during their regularly scheduled maintenance outages.

Notified R1 DO (Newport), R2DO (Sykes), R3DO (Bloomer), and R4DO (O'Keefe). Notified Part 21 Group via E-mail. Notified NRR and NRO via facsimile.

*.* * UPDATE AT 1528 ON 2/8/2011 FROM VICTOR APOSTOLESCU TO MARK ABRAMOVITZ ***

Velan Inc. has issued the final report on this problem with no changes from the January 14, 2011 update.

Notified R1 DO (Bellamy), R2DO (McCoy), R3DO (Duncan), and R4DO (Clark). Notified Part 21 Group via E-mail.

Received at: 02/08/2011 15:28

Feb, 8, 2011- 3:23PM __ Velan Sales Williston 8028653030VVELAN

No, 1040 P. 1

FAX TRANSMISSION

SEND THIS FAX TO TELEPHONE NUMBER: (301) 816-5151

TO: U.S. Nuclear Regulatory CommissionDocument Control DeskWashington, D.C. 20555-0001

ATTENTION: Document Control Desk via fax (301) 816-5151

DATE: February 8, 2011

FROM: Victor ApostolescuVice President Quality AssuranceVelan Inc.

TELE: 514-748-7748Ext. 1134

victor.apostoles cuavelan.com

NUMBER OF PAGES INCLUDING TRANSMISSION PAGE: 14

SUBJECT: FINAL REPORTFlowserve, Limit switch on Limitorque ActuatorsType SMB-00 and Type SMB-2-06

Please see attached letter.

Feb. 8, 2011 3:23PM Velan Sales Williston 8028653030 No. 1040 P. 2

VELAN Inc.7007 Cote de Liesse, MontrealQuebec, Canada H4T 1G2Tel: (514) 748-7743 Fax: (5`14) 748-7592

January 20,2011

U.S. Nuclear Regulatory CommissionDocument Control Desk

Washington, D.C. 20555-0001

Attention: Document Control Desk, via fax 301-816-5151

Subject FINAL REPORTFlowserve, Limit switch on Limitorque Actuators, Type SMB-O0 and Type SMB-2-06

Gentlemen.

On January 14, 2011 Velan received from Flowserve the Final Report for Velan CAR 25500-73903 / Part 21Evaluation of Geared Limit Switch (NRC Event # 48403).

Following our review of aforementioned document it was determined that In general it answers all ourconcerns; additional clarification was requested from Flowserve on the issue of corrective actions taken inassembly as well as any other departments or processes. The verbal explanation provided by Mr. JeffMcConkey, Limitorque QA Manager, was deemed satisfactory and we therefore decided to accept theconclusions of the report.

As a temporary measure we have Instituted additional verifications that will be performed after the functionaltest of actuated valves equipped with the subject actuators and geared switches:

verification of electrical continuity (using an ohmmeter), andverification that the finger contact arms are touching the rotor body in the electrically open state.

Please see attached the final evaluation report from Flowserve concerning the limit switches in the subject.

For any additional information on this matter please contact me at 514-748-7748 x 1134 or atvlctor.apostolescu(vetan.com.

Please previde an e-mafl address where a color ADOBE copy of this document can be submitted.

Sincerely yours,

Velan Inc.

Victor Apostolescu, Eng.Vice President Quality Assurance

cc: Flowserve - Jeff McConkey via e-mailVelan - T. Velan, I. Velan, G. Perez, Z. Palko (via e-mail)

CERTIFIED TO ISO 9001 QUALITY STANDARDS

Feb. 8, 2011 3:23PM Velan Sales Williston 8028653030 No, 1040 P. 3

OLimitorque ActuatorsFLOWSERVE

NM___ Flot Control Division

January 14, 2011

To: Velan Inc

Subject: Final Report for CAR 25500-73903 / Part 21 Evaluation of Geared Limit Switch (NRC Event # 46403)

Background:

Velan reported they had an actuator become unresponsive after several cycles of open and close. ReferenceVelan order 219446 (DR 25500). They also reported the same condition on Velan order 217869 (DR73903).Verifying the source of the problem they found several gear limit switch finger assemblies damaged or bent.They also reported that some of the finger assemblies were tight with very little spring action. The followingphotos were attached to the CAR as evidence of these conditions.

2525 and 2526 showed a contact bent at the base near the setting screw2527 showed a very tight finger assembly with minimal spring action2641 and 2642 showed a finger assembly farthest from the base with minimal if any contact with the rotorbutton.2528 showed a finger assembly with normal spring action.

Velan returned all above geared limit switches in question to Flowserve for evaluation

Evaluation / Root Cause:

Flowserve has completed a thorough evaluation of the SMB geared limit switch issue that was reported byVelan in CAR 25500-73903.

The bent finger condition that was noticed in photos 2525 and 2526 was evaluated and found that the finger wasso severely bent that it would not make contact with the rotor button in the closed state. It is Flowserve'sopinion that this damage could have been caused by a flat bladed screw driver catching on the rivet head duringthe switch setting process. While turning the intermittent gear shaft it is possible for the rotating blade of a flatbladed screw driver to contact the spring stud on the contact arm. This creates a bending moment resulting inthe contact arm bending at the point where the spring stud passes through the contact arm. Once discovered, thisfailure mechanism was repeated in multiple trial tests. Subsequent 3-D modeling of the switch assemblyreinforced this finding by identifying the contact area of a screwdriver with the spring stud. The photos belowshow the bent rivet from the above finger assembly and scarring on the head of the rivet

The tight finger condition that was shown in photo 2527 was found to be caused by the clearance hole in thefinger for the rivet tobe on the low side of the print tolerance and some of the samples measured showed thehole diameter slightly smaller than tolerance. It was found through the engineering evaluation and 3-Dmodeling that this tight condition could possibly occur even if the hole diameter was to specification and at theminimal print tolerance. We tested multiple finger assemblies with completely tight to minimal spring action for3,300 cycles and found no loss of continuity or bending of the contact fingers. Based upon this testing, it was

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determined that producing a bent finger contact cannot occur during normal cycling operation of the switcheven if the finger assembly is tight with no spring action.

The switch that had the condition depicted in photos 2641 and 2642 was tested as received and passed over2,000 cycles with no loss of continuity. This switch finger was found to have very minimal contact with thebutton in the closed position as a result of the "L" bracket of the finger assembly being bent. This conditionallowed for minute contact with the button but the finger assembly would stay stationary when the switch wentto the closed position. The finger assembly was not tight and had full spring deflection. Unfortunately we didnot notice this condition upon the initial testing which may have been the cause for the intermittent loss ofcontinuity at Velan. This finger assembly was subsequently adjusted properly so the finger was touching therotor body in the electrically open state and the switch was tested an additional 3,300 cycles with no loss ofcontinuity.

The review of purchase orders and material certs of the switch components from 2007 to date showed nochanges had been made to the materials or suppliers. The only deviation in the components found was thespring stud hole diameter on some of the fingers had fallen just below the minimum tolerance which may be acontributor to the tight condition. The switch assembly procedures and processes were reviewed and nochanges were identified.

Corrective Actions:

Based upon this evaluation the following corrective actions have been implemented. The individual switchcomponents have been reviewed and all critical inspection dimensions have been identified. The relevant in-process inspection plan has been reviewed and is being modified to include a visual inspection step to confirmthat the finrger contact arm is touching the rotor body in the electrically open state. This additional inspectionwill be documented on existing inspection form L-193.

Conclusions:

After cycle testing nine (9) switches firom Flowserve stock, and seven (7) returned switches from Velan,; it wasdetermined that producing a bend in the contact finger cannot occur during normal cyclic operation of the rotor.A bend in the finger assembly (finger and spring stud) with the use of a flat blade screw driver was duplicatedseveral times. This can happen when turning the intermittent gear shaft during the GLS setting procedure. It wasrecreated in the 3-D solid models as noted above. This occurs only on the finger assemblies designated as 4Land 8R due to the lever action that can be produced as shown in the models. It is highly likely that this is thecause of the bent finger assemblies reported in the CAR. Evidence of the bent spring stud and scuff marks onthe head of the stud are in support of this argument.

It is potentially possible a bend could result from a flat blade screw driver being wedged between the fingerassembly and the contact button; however, it is highly unlikely.

The most significant event occurred during testing of the Velan switch from actuator serial # L852269. Thisswitch, as with all of the returned Velan switches, was tested first in the as received condition. The loose fingerbase was tightened. No adjustments were made to any of the finger assemblies. Notes were taken to documentwhich finger assemblies were "very tight" and which were not. This switch had several "very tight" fingerassemblies. Visual inspection did not reveal any obvious bent finger assemblies. All contacts had initialcontinuity; however, with contacts in the open electrical state, finger contact with the rotor body was notverified. During the testing at 1,057 cycles continuity was lost on contact 4. The switch was allowed tocomplete the 2,000 cycle test. No additional contacts lost continuity. Visual inspection of contact 4 revealed thatfinger assembly 4L was no longer touching the rotor button. 4L was not a "very tight" finger assembly. Afterremoval and closer inspection of the finger base from the gear frame it could be seen that there was a slight

Feb. 8, 2011 3:23PM Velan Sales Wil1iston 8028653030 No, 1040 P. 5

bend in finger assembly 4L. The finger assembly was then removed from the finger base. The finger wasdisassembled and inspected. A bend in the spring stud was clearly evident. It is surmised that prior to initiatingthe cycle test the finger of contact 4 (switch state open) was not in contact with the rotor body, and incombination with the bent finger, bent spring stud and deformed cotter pin hole; produced dynamic mechanicalreactions that eventually resulted in contact 4 losing electrical continuity. High powered macro photos weretaken to look for any other damage. The photos revealed a scuff mark on the underside of the spring stud head.This scuff mark supports the argument that the edge of the flat blade screw driver can get caught under thespring stud head. When the screw driver is rotated, it pulls on the head and then pulls the finger andconsequently both will bend. The force is great enough to damage the cotter pin hole in the spring stud. It wasdecided to reassemble the finger assembly, readjust the finger assembly and retest. The readjustment consistedof bending the "L" bracket enough so that the finger is touching the side of the rotor body. The switch wastested again. It was decided to extend the test for the 60 year life of 3,300 cycles. The switch functionedproperly with no loss of continuity on any of the contacts. To further substantiate that a bent finger assemblycan be readjusted and maintain proper continuity, a similar switch was built from Flowserve stock and wastested for 3,300 cycles with no loss of continuity.

Visual inspections and macro photography of the finger assembly 4L of switch in photo 2652 revealed a verysevere bend in the finger and spring stud, and severe deformation of the cotter pin hole- The scuffing on the topof the head indicates a strong screw driver rotation in the opposite direction. This again supports the argumentof a flat blade screwdriver being used (see photos below).

The model below should be utilized by Velan as a guideline for visual inspection to confirm proper switchoperability.The assembly should be inspected to ensure that there is proper contact with the rotor body.Adjustments to the "L" bracket are permissible..

INTERMITTENT GEAR SHAFT I

BASE

Model shows finger assemblies touching rotor body in the electrically open position

Feb, 8, 2011 3:24PM Velan Sales Williston 8028653030 No. 1040 P. 6

Based on the testing and evaluations of all Velan returned switches and switches from Flowserve stock, a designdeficiency has not been identified. Properly set switches will perform their intended functions. Flowservebelieves that this issue is not reportable to the nuolear industry under the guidelines of 10CFR50 Part 21regulations. A maintenance update will be issued by Flowserve to guide the .industry on any recommendationsduring their regularly scheduled maintenance outages.

Jeff McConkeyManager Quality AssuranceFlowserve - Limitorque

VELAN PHOTO 252571

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IVFLAN PHOTO 2526 1

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VLAN P 2527

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VELAN POTO 2641

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I LANP1H OTO02:6 4:j

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~I VLNPOTO 265T]

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FINOER ASSEMBY FROM VELAN PHOTO2652 SHOWS SCUFF MARKS ON SPRINGSTUD

SiCUFp MARKCS ON THE SPRING STUD

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BENT SPRING STUD WITH DAMAGE TOTHE COTTER PIN HOLE

I LAST PAGE OP REPORT